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. 1997 Aug;73(2):1110–1117. doi: 10.1016/S0006-3495(97)78143-8

High-gain, low-noise amplification in olfactory transduction.

S J Kleene 1
PMCID: PMC1181007  PMID: 9251827

Abstract

It is desirable that sensory systems use high-gain, low-noise amplification to convert weak stimuli into detectable signals. Here it is shown that a pair of receptor currents underlying vertebrate olfactory transduction constitutes such a scheme. The primary receptor current is an influx of Na+ and Ca2+ through cAMP-gated channels in the olfactory cilia. External divalent cations improve the signal-to-noise properties of this current, reducing the mean current and the current variance. As Ca2+ enters the cilium, it gates Cl- channels, activating a secondary depolarizing receptor current. This current amplifies the primary current, but introduces little additional noise. The system of two currents plus divalent cations in the mucus produces a large receptor current with very low noise.

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Selected References

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